Brake lights are standard equipment in many vehicles including automobiles designed to drive on public roads in the United States or other countries. Brake lights may be provided in any of various forms, but are typically provided as incandescent bulbs or LEDs. The term “brake light” as used herein is intended to refer to any illuminating device intended to indicate braking, deceleration, or stopping of a vehicle, including incandescent bulbs or LEDs. Brake lights are sometimes referred to by other terms such as “stop lamps” or “brake lamps”, and such terms are used interchangeably herein.
Stop lamp flasher devices of various designs are known in the art. Stop lamp flasher devices are typically configured to turn a CHMSL (center high mounted stop lamp) or other brake light on and off rapidly (or vary the power output of the brake light) the in order to alert a driver behind a stopping vehicle that the flasher-equipped vehicle is stopping. The flashing lights associated with stop lamp flasher devices generally obtain the attention of a trailing driver more quickly, thus providing the trailing driver with additional time to respond to the braking vehicle in front of them. In addition, persons who frequently drive in stop-and-go city traffic may become less responsive to ordinary brake lights, and the flashing lights associated with stop lamp flasher devices may be used to gain the attention of these drivers on shorter notice. An exemplary stop lamp flasher device is shown in U.S. Pat. No. 5,565,841, the entire contents of which are incorporated herein by reference.
Many stop lamp flasher devices do not actually turn the brake light on and off, but instead modulate or vary the power output by the brake light. For example, a stop lamp flasher device may rapidly vary the power output from a brake light between 100% and 50% (i.e., a first power output being 100% and a second power output being 50% of the first power output). As such, stop lamp flasher devices may be considered to “pulse” the brake light instead of flashing the brake light. However, because this pulsation is relatively rapid, a human is typically unable to determine whether the brake lamp is pulsating or flashing. Therefore, the terms “pulse” and “flash” are used interchangeably in this document to simply refer to some relatively rapid variation in the power output from a vehicle, whether between 0% and 100%, 50% and 100%, 40% and 90% or any other power variation.
Most stop lamp flasher devices are offered for sale in the aftermarket and either installed by the owner of an existing vehicle or by dealers prior to the sale of a vehicle. Thus, existing stop lamp flasher devices are typically installed on new or used vehicles at the time of sale, after the vehicle has left the manufacturer's factory. One issue with existing stop lamp flasher devices is that they may not operate properly with certain modern automobiles that include automated computer diagnostic capabilities. In particular, when a stop lamp flasher device is installed in these automobiles, the fault detection circuitry may improperly detect that there is a problem with the brake light. For example, the fault detection circuitry may not expect any varying current across the brake light during braking, and therefore may consider varying current across the brake light as a fault. When the fault detection circuitry improperly detects a problem with the brake light, a warning indication may be presented to the vehicle operator on the dash or other vehicle location. This indication may be annoying to the vehicle operator and cause concern even though the stop lamps are indeed functioning properly. Alternatively, a detected problem with the brake lamp may cause some vehicles to suspend operation of the brake lamp for some period of time.
Another potential issue with stop lamp flasher devices is that the aftermarket installation process involves cutting the brake light wiring (i.e., cutting wires in a wire harness that leads to the rear stop lamps). After the brake light wiring is cut, the stop lamp flasher device is coupled to the brake light wiring in order to effect the desired pulsing effect for the CHMSL or one or more additional brake lights. However, the process of cutting the brake light wiring and installing additional circuitry is not without issues. For example, a dealer or new car owner may find it stressful or somehow improper to cut into operational brake light wiring of a new vehicle in order to insert additional circuitry. Moreover, it is typically time consuming for even well trained technicians to identify the brake light wiring on various vehicles and insert the stop lamp flasher device in the appropriate location. Therefore, existing stop lamp flasher devices leave room for improvements with respect to ease of installation. Additional opportunities to improve existing stop lamp flasher devices are presented with respect to size reduction and production costs, and easier and quicker installation of the devices.
Yet another issue with existing stop lamp flasher devices is that they may not always effectively pulse the lights in different vehicle types having different types of stop lamps and different numbers of brake lights. For example, if the stop lamps are to be pulsed by repeatedly changing the light intensity from bright to dim, without turning the stop lamps completely on and off, existing stop lamp flasher devices may only be configured to work with certain vehicles having certain types of stop lamps. For example, a particular stop lamp flasher device may be configured to work only with LED stop lamp arrangements, but not with incandescent stop lamp arrangements, or with stop lamps having only a certain number of stop lamps.
In view of the foregoing, it would be advantageous to provide a stop lamp flasher device that works with modern vehicles that include fault detection circuitry for the brake light circuit. It would be advantageous if such device could be easily installed in an existing vehicle by simply coupling additional circuitry to the brake light circuit in the vehicle. It would also be advantageous if the stop lamp flasher device could be produced at relatively little cost and with a relatively small package size. Additionally, it would be advantageous for the improved stop lamp flasher device to be configured for use with vehicle braking circuits on numerous different vehicles, regardless of the number of stop lamps used by the vehicle or the type of stop lamp used.